Members of NATO regularly participate in exercises together (Picture: MOD).
Germany would be unwilling to defend the United States in the event of an attack from Russia, a new study has suggested.
Research conducted by YouGov has also found that support for NATO membership has fallen among a number of European nations.
The Article 5 commitment of the alliance partnership states that an attack on one is an attack on all, meaning that all member countries are obliged to defend one another.
The citizens of four NATO nations (the UK, France, Germany and the US) were surveyed about this commitment, with majorities in all the countries backing the pledge.
However, this changes when the public was asked about defending 13 specific countries.
The study asked whether the respondent's country should be willing to use military force if Russia were to attack the following list of NATO member countries: Croatia, France, Germany, Greece, Latvia, Poland, Romania, Turkey, the UK and the US.
Respondents were also asked about non-alliance members Finland, Sweden and Ukraine, who could be Russian targets in the event of an attack.
As well as being unwilling to defend the US, the study suggested Germany would be unlikely to defend Ukraine, Romania and Turkey.
France would also be unwilling to defend the latter three nations, according to YouGov.
The publics of Germany, France and US were all more willing to defend the UK than not in the event of a Russian attack.
Turkey, despite its NATO status, seemed to be the country most were most reluctant to defend.
The US was in favour of defending Turkey, while Britons were split with a 31% to 31% divide as to whether they would defend them, with both Germany and France opposed defending them by a big margin.
It was also the German and French public who were not in favour of defending Ukraine or Romania either.
The US was also not gaining the support of Germany, as they objected to defending the US, whereas the US public thinks they should defend Germany should it find itself under attack.
Another finding from the report was the decrease in enthusiasm amongst the public about being a member of NATO.
Overall, more people are happy to be part of NATO but the number is declining.
In 2017, 73% of Britons approved of their membership. However, that figure has since fallen to 59%.
Support has also fallen in Germany, France, Denmark and Norway, the study suggests.
Two years ago, Donald Trump described NATO as "obsolete", and the survey in America did suggest a decrease in their public thinking NATO plays an important role in their national defence.
Americans are less enthusiastic about NATO membership than their European counterparts.
NATO Secretary General Jens Stoltenberg this week thanked President Trump for his "strong leadership" in calling for member countries of the alliance to increase defence spending.